Mast Therapeutics (MSTX) has agreed to acquire Aires Pharmaceuticals, a privately held clinical-stage company developing therapies for pulmonary vascular disorders, in an all-stock deal.
Aires' lead product, AIR001, has orphan-drug status in the U.S. and Europe for pulmonary arterial hypertension.
Under the terms of the transaction, Aires will receive shares representing 6% of Mast's commons stock.
Adam Feuerstein tweets that Mast is "paying 6M shares of stock for Aires, or roughly $5M." Feuerstein also notes that Novartis had an option to acquire Aires but has apparently decided not to take it.
Notwithstanding, Mast's shares are +5%. (PR)